This invention relates generally to filters for IV sets and the like for intravenous administration of fluids. More particularly, the present invention relates to a filter assembly in which a sub-micron filter element is utilized. Such filters require increased surface area in order to function with standard gravity IV sets. Large filters, however, are bulky and difficult to place near the site of injection. Moreover, in prior art filters for IV sets and the like which utilize sub-micron filter elements, air entrapment is a problem.
With the present invention, a flat profile filter is provided which lends itself to placement near the final section of IV tubing, or in other words, near the site of injection. Further, the present invention enables a much larger filter area to be used than in prior art devices, with a resultant increased flow rate. Additionally, the filter according to the present invention eliminates the problem of air entrapment, and in the present invention, incoming fluid pushes or channels the air ahead of it, pushing the air through the filter and into the housing or case, where it is easily dispersed by tapping or shaking the case or housing. Additionally, a filter in accordance with the present invention can have essentially twice the filtration area within the confines of the same size housing by simply providing a frame having both sides thereof open and sealing a filter element over each opening. Such a double filter assembly is desirable, for example, in situations where adequate flow rates cannot be obtained with a single filter, or when the volume of fluid to be infused exceeds the filtration capacity of the single filter. Further, the elongate flat housing near the injection site provides a gripping means to facilitate manipulation of a needle and the like.